The Worm Turns: It's Down
To No Good off Home Turf

When Cindy Hale hikes through stretches of the Chippewa National Forest in north-central Minnesota, she sees the depredations of her sworn enemy all around her.

The colorful spring flowers that once bloomed are all but gone. Ferns and the seedlings of sugar-maple trees are in short supply. The thick, spongy forest floor that cushioned every step has disappeared, leaving bare dirt. There are fewer ovenbirds, warblers that rely on the...